Coincidence-telemeter.



O. EPPENSTEIN. CONGIDENCE TBLBMETER. APPLICATION FILED FE1-3.26, 1913.

1,1 17,8%@ Patented Nov, 17, 1914.

OTTO EPENSTEIN, OF JENA, GRMANY, .ASSIGNOR T THE FIRM 0F CARL ZEISS, 0F

JENA, GERMANY.

CONCIDENCE-TELEMETER,

Specicaton o! Letters Patent.

Patented Nov. 17, i914.

Application filed February 28, 1913. Serial No. 751,361.

To all whom, it may concern Be it known that OTTO Errnxs'rnin, a citizen of the German Empire, residing at Jena, Germany, have invented a new and useful Coincidence-Telenieter, of which the following is a specification. l

The present invention relates to coincidence teleineters, which have two double iinages of different magnification available tor measuring purposes. This result has so tar been obtained by arrangements, which allow of one and the saine double image being observed alternately under one and the other ma Unification. In order to change. the niagnification the observer' has to perform a change-over, e. g. he has to slid* an imageerecting lens-system (a lens-system of -reversion) in the ocular from one operative position into the other. 1

According to the present invention the two double images are presented simultaneously, two oculars being use Whenthe observer wishes to pass Jfrom one iiiagmiica tion to the other, it is only necessar)Y for him to move his eye from one ocular to the other.

Telemeters presenting two double images and having two oculars are known, c. y. as stereoscopic ones, in which there is presented to the left and the right eve respectivelv a double image to be merged into one spatial double image (German pa tent speciiication 162-171 and patent specilicalion 1,013,849), but also as binocular ones with identical double images (British patent specification 9306/1911) and as coincidence telemeters with inversion ot the upper single image in one double innige and of the lower single image. in the other one {(ieil` man patent specification 231101) In the last-named case the tour (half) single im ages are obtained by means of a separating prisiiisvstein without a rail loss ot light from the complete images'formcd by the left-hand and the right-hand objective system. All the means suggested in the aboveincntioned publications for the provision of the two double images can serve the purpose ot' the present invention, when they are combined wit-li means, for giving the two double images different niagnifications. Thus, c. g., as in the above-mentioned coincidence telemeter the twee double images, which are formed by a separating p rism system, .may be made use plan respectivelyv of the of, when the difference of magnification is produced by the disparity between the two ocular systems. Where a reduction of the luminosity to one halt'its value is of no consequence one of the two mixed raypencil-systems, which are furnished by the separating prism-system and produce double images, ma)Y be allowed to be lost and the other may be split by welllmown means into two pencil-systems, each of which then again furnishes a double image. When with the new telemeter the two oculars are so disposed that/their axes of emergence are parallel to one another and lie at the interocular distance, the observer can even change the magnification, without having to move his head, by observing, instead of with one of his eyes, with the other one. It will be tound convenient in this case to fit a screening device, which mav be given two operative positions in such a manner that it liberates one ocular or the other.

In the annexed drawing: Figures l and Q are diagrammatic views in elevation and optical system of one torni ot' the teleiiieter accordii'ig to the invention, the ocular lenses being omitted. Fig. 23 is a section on line 3--3 of Fig, l, showing the separating prism-sistem and the two ociilai's. Fig. -i is an axial section in thc plane of' triangulation oi a const-ructional forni of a telemeter. Fig. is a section on line 5-5 ot Fig. Jr,

l'ii the telemeter Figs. 1 to 3, in either double image one single image erect, the other is inverted. ln one double image the erect single innige lies above, in the' other below the line oi coincidence. To the-separating prism-system al, ai' the ray-pencil s vstems coming t'rom the objective s vstems Z1. 7i are transmitted by means of two reflectiner prisms l and c2, which are cemented to (z and af, resi'iectivcly. The reanportion ot' the cement-laver ot the. said separating prism-svsteni is replaced b v a separating 100 laver a", which is reflecting on both sides.

Of the two double images formed in this separating prism-system one is observed through the ocular d1, c1, the axis of which inclined upward. In this double image 105 the erect single image lies above the line of coincidence, which is formed by the front edge of the separating layer a0. The said single image is derived from the left-hand objective system, and the lower inverted 110 CIV.

e2', which is inteeded'fon horizontal inspec-v tion and compriscsa reflecting prism f. ln

vthis double image the erect single image lies below the line ci coincidence and is derived from the lethariel olojfective system, while the upper single image is a right-hand image and is inverted. The coiltrast between the two double images, that in one of them the left-hand single image lies uppermost and in the other the right-hand one, ceases, when the re'llectirie prism f is omitted or just such a prism is introduced into the ocular (Z1, el. in the example shown, corresponding to the shorter focal length of the ocular all, c1 the double image presented oy it is the one haviiig the greater magiiilication. The displaceahle glass wedge g indicates the measuring device.

la the double images presented by the coincidence telemeter, Figs. and 5, both single images are erect. The two oculars have in this example interoeular distance and are parailel to each other and the plane oi triangulation. The cement-layer of the separating prism system k1, Il: is again replaced as to its upper half by a separating layer h, which is reflecting onhoth sides. r he mixed ray-pencil-system, which emerges from this separating prism-system perpendicularly to the base-line, is received by the right-hand. ocular ola, e. ln the double image presented by this ocular the lower single image is derived Jrom the left-hand objective system, the upper single image from the righthand one. The mixed raypencil-system emerging toward the left and parallel to the oase-line from the separating prism-system is received by the left-hand ocular, which is formed as a terrestrial ocular and consists of the following parts: a collective lens L, a reflecting prism 7c, a lens of reversion t, a field lens CZ* and an eye lens et. in the double image presented by this ocular the upper single image is derived from the left-hand objective lower single image Jrom the right-hand one. lt is assumeohat by .the lens of reversion Z the douole image is reduced, so `that the larger double iirage is presented by theV right-hand ocular. A screen m can he displaced parallel to the oase-line by means o a pin m in guides n between two stops o1 and 02,' according to its position it closes the right-hand or the left-hand ocular. For dciecting the ray-pencil-system coming from the ri ght-hanfl objective system, while nding a range, a glass wedge g is again emplayed, which may be displaced parallel to the base-line by means of a rack g", a pinion 7) and a milled head p". A scale g2, which is connected with the carrier g1- o the wedge, and the index q belonging to this scale are visible through a window r.

'l claim:

i. in a concidence telemeter two objective systems,'a separating prism system, two ocularrsystems, each of which has a diirent power and icomprises lar, and a measuring device, the said separating prism system being adapted to halve the two images presented by the said objective systems, to compose two double images from these four half images and to present the said two double images simu taneously to the said two ocular systems.

3. ln a coincidence telemeter two ohjee-tive systems, a separating prism-system, two astronomical oculare having different powers and a. measuring device, the said separating prism-system being adapted to halve the two images presented by the said objective systems, to compose two double images from these four half images and to present the said two double images simultmeousl)y to the said two oculars.

ofrfro eeeeus'rem.

Witnesses PAUL KRGER, RICHARD HAKU.

system, the

an astronomical ocu- 

